Electrolytic manufacture of iron and its alloys



Patented Feb. 20, 1934 UNITED STATES ELECTROLYTIC MANUFACTURE OF IRONAND ITS ALLOYS Ernst Kelsen, Vienna, Austria, assignor to Kelsen SpecialSheet Holding, S. A., Luxemburg, Luxembnrg, a limited company ofLuxemburg No Drawing. Application March l'l, 1933, Serial No. 661,417,and in Austria April 22, 1931 2 Claims. (01. 204-1) Difficulties are metwith in the manufacture of chemically pure iron by electrolytic refiningowing to the anode material containing metalloids, such as sulphur andphosphorus, which are present for example when using cast iron scrap.The anodicsolution always takes place with a slightovervoltage, so thatat least partial oxidation of the sulphur to S04-ion occurs. It is easyto satisfy oneself by analysis that this ion is present in such arefining electrolyte.

The iron raw material, however, is not the only source of sulphur,because both acid and water which must be added throughout the durationof the electro deposition, contains as a rule a 29 certain amount orBot-ion, which also has to be removed.

It is desirable to remove the 804-1011 thus formed from the electrolyte,which, when manufacturing iron, consists mainly of ferrous chloride,with or without an additional salt, and which, when manufacturingalloys, consists of salts of those metals of which the alloy consists,also with or without an additional salt, preferably sodium chloride,because, in view of go'the considerable hydrogen overvoltage at thecathode, the SO4-ion undergoes partial reduction, gives up its sulphurcontent to the electrolytic iron. and thereby impairs the magneticproper-,

anodes) containing sulphur, characterized in. 40 that the electrolytecontains besides the iron salt, or the salts of those metals of whichthe alloys consist, one or more additional salts where of at least onegives such a cation, that it gives an insoluble precipitate with804-1011. Such an aadditionalsaltmaybeaddedaloneasacon ducting salt, orit may be added together with another conducting salt. 7

Conveniently, barium chloride or some other suitable -barium salt isadded to the electrolyte as a conducting salt. The SO4-ion then forms aninsoluble barium sulphate fwhich readily settles and may be removed fromtime to time by filtering the electrolyte.

It has heretofore been proposed in certain cases to use CaCl: as anadditional salt in an 35 iron salt electrolyte. The purpose of. addingthis salt was, however, quite different from thataimed at by the presentinvention. The object of adding this salt heretofore was either toimprove the electrolytic conductivity or to work at temperatures near orabove 100 centigrade, whilst, according to the presentinvention, theobject is to remove from the solution practically the whole content ofthe SO-i-ion. For the first mentioned cases it was necessary to addconsiderable quantities of the salt to attain success, whereas for thepurpose of the present invention,

a relatively small amount of such a salt is sufilcient;

I claim: g

1. In a process of preparing electrolytically manufactured iron ofimproved magnetic qualities from raw materials containing sulphur, thestep of reducing the sulphur content of the electrolytically producediron by adding to the elecg5 trolyte containing the iron-salt a salt ofan alkaline earth metal which, possesses a cation which yields aninsoluble precipitate-with Sol-ion, m an amount suflicient to completelyeffect such precipitation.

2. In a process of preparing electrolytically manufactured iron ofimproved magnetic qualities from raw materials containing sulphur, thestep of reducing the sulphur content of the electrolytically producediron by adding barium chloo5 ride to the electrolyte containing the ironsalt in an amount sufficient to completely precipitate all of thesOi-ion.

ERNST KELSEN.

